As one of the Real Housewives of Orange County, Tamra Judge is known to be outspoken about…pretty much everything. And in a photo she posted on Instagram a few days ago, Judge got honest about a health issue that put her bodybuilding ambitions on hold: She was recently diagnosed with melanoma in a very sensitive place.

The mirror selfie shows Judge wearing denim shorts pulled up to reveal a tiny freckle on her butt cheek. She wrote in the photo's caption that she was planning to take part in a bodybuilding competition this November at the age of 50, but life had other plans. "[I'm] showing you this picture because this is what melanoma looks like," Judge wrote. "I don't want sympathy, I want you to save YOUR ASS and get your skin checked. This was just a small black flat freckle.... I had no idea!" She continued, "I've been a little sad, worried and pissed off. But we caught it early and that makes me happy."

Judge also posted earlier this year about getting two spots on her skin "cut out," and asking her followers to get their skin checked.

Melanoma only accounts for about 1 percent of all skin cancer cases, according to the American Cancer Society (ACS). But it's the deadliest type of skin cancer, with more than 9,000 Americans dying from melanoma each year, according to the CDC. Mary Stevenson, M.D., assistant professor of dermatology at NYU Langone Health, tells SELF "it's a cancer that arises from the melanocytes in your skin," which are the cells that produce the pigment of your skin, and it causes new moles or changes existing ones into cancerous ones.

Researchers don't totally know what causes melanoma, Dr. Stevenson says, but being exposed to UV light—via tanning beds or good old-fashioned sunlight—definitely increases your risk for developing it. According to the CDC, more than 90 percent of melanoma cancers are "due to skin cell damage from ultraviolet (UV) radiation exposure." Having fairer skin, a history of blistering sunburns, or a family history of skin cancer increase your risk as well, she says.

Luckily, melanoma is usually easily treated if it's caught in an early stage, as was the case with Judge's. The Mayo Clinic says treatment at this point is to surgically remove the melanoma, which is all that's required in many cases. However, if the melanoma spreads beyond the skin, it can require more extensive treatment.

Melanoma can develop even in places that don't see the sun.

As Judge's case highlights, not all melanomas are in obvious places. "We do have melanomas develop in areas where the sun doesn’t necessarily shine," Dr. Stevenson says. For instance, they can develop between your toes, under your nails, in your eye, or even in your vagina. Dr. Stevenson says these "hidden" melanomas are actually more common among those patients with darker skin who may not necessarily think they're at a high risk for skin cancer.

That means it's crucial to do what you can to prevent melanoma: The ACS suggests using sunscreen correctly, sticking to the shade when you're outside, wearing clothes if you're hanging out in the sun (including a hat!), and avoiding tanning beds.

In addition, as Judge's post says, get acquainted with your skin. Dr. Stevenson recommends that everyone get a thorough check by a dermatologist once a year. And we do mean thorough: "You don’t want to be in a bra and underwear during the exam," she says. You should also be sure to remove any nail polish so your derm can look at the tissue under your nails. Additionally, the ACS also suggests doing your own skin exams once per month. Try getting a partner, roommate, or double mirror to help out with those hard-to-see areas, Dr. Stevenson says.

And what kind of moles are you on the lookout for? Follow the ABCDE rule: A stands for asymmetrical, B stands for border, C stands for color, D stands for diameter, and E stands for evolving. So, if you see a mole that isn't symmetrical, has an irregular border, is more than one color, has a bigger diameter than the tip of a pencil, or seems to be evolving or changing, get it checked out.

Not all atypical moles are necessarily the same level of worrisome, though. Indeed, there's a "spectrum of atypia," Dr. Stevenson says, with those on the milder end not necessarily needing any further action and those on the severe end treated as melanoma "to be safe." So, if you have any questions about a mole that looks out of place, your derm can set you straight.